Lawn mower apparatus

ABSTRACT

Apparatus for controlling operation of a self-propelled lawn mower for moving a circular lawn area. The apparatus includes a reel located at the center of the circular area and a line wound on the reel and attached to a front corner of the lawn mower for controlling the lawn mower movement so that it moves in a decreasing spiral path to mow the circular area around the reel. A stop mechanism is provided for automatically stopping operation of the self-propelled mower when it nears the center of the spiral path near the reel.

United States Patent 1191 Jensen July 10, 1973 [54] LAWN MOWER APPARATUS3,627,071 12 1971 Haupt 180/79 7 [75] Inventor: Warren Jensen, Atco, NJ.

Primary Exammer-Antoma F. Gulda [73] Ass gneez Atco Enterprises, Atco,NJ. A0mey ]ohn p Barley [22] Filed: Mar. 31, 1972 21 Appl. No.: 239,907[571 ABSTRACT Apparatus for controlling operation of a self-propelled[52] U S Cl 56/10 2 56/1); 15 180/79 lawn mower for moving a circularlawn area. The appa- [5 H 75/00 ratus includes a reel located at thecenter of the circu- [58] Fie'ld 5 DIG lar area and a line wound on thereel and attached to b 3 l a front comer of the lawn mower forcontrolling the lawn mower movement so that it moves in a decreasing[56] References Cited spiral path to mow the circular area around thereel. A stop mechanism is provided for automatically stopping UNITEDSTATES PATENTS operation of the self-propelled mower when it nears thelg; 51 22:"!

center of the spiral path near the reel.

212591193 10/1941 Andrew 56/DIG. 15 9 Claims, 5 Drawing Figures LAWNMOWER APPARATUS BACKGROUND OF THE INVENTION The invention relatesgenerally to self-propelled lawn I mowers and more particularly to lawnmowers which can operate unattended and are self-propelled to mow apredetermined area of a lawn.

The advantages of a self-propelled lawn mower of the indicated type ineliminating manpower are self evident. While various types ofself-propelled lawn mowers have been provided, these prior art devicesare very expensive to make and very complicated in operation andmaintenance. Typical of these prior art devices are those shown in U. S.Pat. Nos. 2,521,262, 3,570,227, 3,550,714 and 2,941,346.

SUMMARY OF THE INVENTION It is the general object of this invention toprovide a self-propelled lawn mower which is operated unattended to mowa predetermined lawn area and the operation of which is terminatedautomatically at the end of this lawn mowing procedure. It is a featureof the invention to provide a lawn mower of the indicated type which issimple in construction, easy to maintain and simple in operation.

Briefly stated, the general object of the invention is achieved by theprovision of an apparatus for controlling the operation of apower-operated, self-propelled lawn mower to mow a predetermined area byselfpropelled operation which comprises a reel means anchored in astationary position at the center of the lawn area to be mowed, a linemeans secured at one end of the reel means and at its other end on thefront corner of the lawn mower so that as the lawn mower isselfpropelled it will move in a decreasing spiral path around the reelmeans winding the line means thereon, and means for auotmaticallystopping operation of the lawn mower at a location close to said reelmeans after said lawn area has been mowed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top plan view showing thelawn mower apparatus in accordance with the invention;

FIG. 2 is an end view of the apparatus shown in FIG.

FIG. 3 is a side view of the apparatus shown in FIG. 1 taken generallyon line 3-3 of FIG. 1;

FIG. 4 is a sectional view of the reel means; and FIG. 5 is a schematicview illustrating the operation of the apparatus in accordance with theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT While the inventionwill be described herein as adapted for use with a self-propelled lawnmower, it is applicable for use with other types of similar machines,such as tractors, planters and other agricultural machines. Thus, asused herein, the term lawn mower is intended to include, whereappropriate, similar types of agricultural machines.

In FIGS. 1 and 3 there is shown a conventional selfpropelled lawn mowerof the rotary type which is powered by a gasoline engine 12. The engine12 is bolted to the mower housing and is provided with the usual sparkplug 14 for the ignition system which maintains operation of the engine.The sparking current is supplied to the spark plug 14 by way of a cable15 from a spark generator as is conventional. The mower comprises theusual deck 16 and four wheels 18, the front pair of which are driven bythe engine 12. There is also provided a discharge chute 20 which isarranged to discharge the cuttings from the side of the mower. A handle22 is pivotally mounted on the rear part of deck 16 at a support means24 and carries at its upper end the usual engine and drive controls (notshown).

In accordance with the invention, apparatus is provided for attachmentto the lawn mower 10 for controlling or guiding the self-propelledmovement thereof in a decreasing spiral path about a central point tomow a generally circular area. Such means comprises a reel 30,preferably made of a strong plastic, and including a pair of disc-likeends 32 joined bya cylindrical portion 34. Reel 30 is mounted at itscentral portion on a pipe 36 by means of an upper collar 38 and a lowercollar 40 secured to the upper and lower ends 32 by suitable mountingscrews which cooperate with nuts as is shown in FIG. 4. The upper andlower collars 38 and 40 are adapted to engage the upper and lower endsof the central pipe 36.

Suitable means are provided for anchoring the reel 30 in the ground inthe position shown in the drawings. Such means comprises a pipe 42, theupper end of which is threadedly engaged with the lower collar 40 toextend downwardly therefrom into an anchoring means 44 securely mountedwithin the ground. The anchoring means 44 comprises a pipe 46 with itstop flush with or below the surface of the ground. Pipe 46 is adapted toreceive pipe 42 internally and is provided with a pair of slots 47 intowhich the outer ends of a pin 48 on pipe 42 are positioned. Each slot 47consists of a vertical slot extending downwardly from the upper end ofpipe 46 to join with a horizontal slot extending around pipe 46. Pipe 46has a pair of anchor plates 50 and 52 extending laterally therefrom atgenerally right angles as shown in FIG. 4. These plates 50, 52 serve tosecurely anchor the pipe 46 in the ground. Also, since the pipe 42 isfirmly positioned in the pipe 46, pipe 42 anchors the reel 30 in theground as shown in FIG. 4. Pipe 42 is inserted into anchoring means 44as desired by sliding both ends of the pin 48 into slots 47 and turningpipe 42 into locking position with both ends of pin 48 in horizontalportions of slots 47. Pipe 42 is removed from anchoring means 44 byturning pipe 42 into unlocking position and moving the ends of pin 48upwardly in the vertical portions of slots 47.

There is provided a line means, preferably in the form of a plastic rope60, which is connected between the reel means 30 and the lawn mower 10.To this end, the rope 60 has one end tied to a lug 62 mounted on the endof an extra long mounting screw 64 whihc is used to mount the lowercollar 40 on the lower end 32 of the reel means 30. The rope 60 extendsfrom lug 62 through an opening 64 in cylindrical portion 34 to theoutside of the reel. As is best shown in FIGS. 1 and 3, the other end ofthe rope 60 is tied to a latch 67 removably connected to a bracket 68mounted on the left front corner of the deck 16 of the lawn mower 10 asviewed in FIG. 1. Latch 67 is constructed to be releasably connected tobracket 68.

By reason of this arrangement, the line 60 serves to control themovement of the self-propelled lawn mower 10 in a path forming adecreasing spiral around the reel means 30. This is illustratedschematically in FIG. 5. It will be apparent that as the lawn mower isdriven in a forward direction, the line will wind on the cylindricalportion 34 of the reel means 30. Accordingly, the lawn mower must movein a decreasing spiral path around the reel means 30. The sequentialstages in this spiral movement are illustrated in FIG. 5.

It will be noted that with each revolution, the distance the lawn mower10 is from the center of the reel is lessened by a distance equal to thecircumference of the reel means. Accordingly, the reel 30 is designed sothat this circumference is somewhat less than the cutting width of thelawn mower so as to insure that with each successive revolution, thereis a slight overlap in the cutting path of the lawn mower. For example,with a conventional lawn mower having a 22 inches cutting width, thecircumference is designed to provide for an overlap of two to threeinches. Also, a typical length for the rope 60 is fifty feet so as tomow a generally circular area of lawn having a diameter of up to about ahundred feet.

At the left in FIG. 5, there is shown at A, B and C three successivepositions of the lawn mower 10 as it makes successive revolutions aboutthe reel 30, it being apparent that there is an overlap in the cuttingarea. The movement of the mower 10 at the region close to the reel 30 isalso shown in FIG. and it is in this region where the line 60 is almosttotally wound upon the reel Means are provided for automaticallystopping operation of the self-propelled lawn mower at a location nearthe reel 30. In FIGS. 1 to 3, the parts are shown at a point when thelawn mower has reached the position whereat it is to be stopped.

To this end, there is provided a bracket 70 mounted on the lawn mower bymeans of a pair of bolts 72 which extend through a slot 74 in avertically extending portion of bracket 70 into threaded engagement withthe housing of the lawn mower. The bracket 70 is located so that ahorizontally extending portion thereof extends over the spark plug 14. Aplate 76 is pivotally mounted on a horizontal portion of the bracket 70by means of a pin 78 secured to a central portion of plate 76, as bywelding, and extending outwardly therefrom into a pair of pivot supportmembers 80 welded onto the top of the horizontal portion of bracket 70.The ends of the pin 78 are rotatably mounted in these support members 80to permit the plate 76 to be pivoted relative to the bracket 70 for apurpose to be described hereafter. The plate 76 is normally maintainedin the position shown in solid lines in FIGS. 1 to 3 by means of atension spring 82 which is connected in tension between a post 84mounted on the horizontal portion of bracket 70 and a screw 86 mountedon the upper end of the stop plate 76. Bracket 70 is provided with astop member 88 which extends vertically upwardly from the horizontalportion thereof to provide a limit for the pivotal movement of the plate76 in the counterclockwise direction viewed in FIG. 3.

The bracket 70 is mounted on the lawn mower so that the lower end of thestop plate 76 is in alignment with the spark plug 14. The slot 74permits the adjustable mounting of the bracket 70 to achieve thisdesired end. Accordingly, the plate 76 may be pivoted in a clockwisedirection as viewed in FIG. 3 to come into contact with the outer end ofthe spark plug 14. The

- bracket 70, the plate 76, the pin 78 and the supports 80 are all madeof metal, or another electrically conductive material, so.that when theplate 76 is pivoted to from the spark plug 14 to the mower, or ground,which serves to prevent the supply of a sparking current to the engine.This short circuiting position is shown in dotted lines in FIG. 3.

Means are provided for actuating the plate 76 from its normal positionshown in solid lines in FIG. 3 to the dotted line position to stopoperation of the lawn mower at a desired location close to reel 30. Suchmeans comprises a contact arm, indicated generally at 90, which ismounted on the upper end of stop plate 76 to extend laterally from theside of the lawn mower 10. The contact arm means 90 is made of twoparts, one part 92 being secured at one end by screw 86 and a screw 94to the upper end of the plate 76. The contact arm means 90 alsocomprises a part 96 which is pivotally mounted on member 90 by a pin 98.Part 96 is secured in the position aligned with member 92 shown in FIGS.1 and 2 by means of a screw which extends through aligned openings inparts 96 and 92 and is engaged by a wing nut 102. Part 96 may be pivotedto a position adjacent member 92 by removing the screw 100, pivoting themember 96 180 about pivot 98 and then inserting the screw 100 through anopening 104 which is now aligned with the opening in member 92. Theretracted position of member 96 is utilized when the mower is to beoperated under manual control.

Means are mounted on the reel means 30 for contacting the arm means 90to cause pivotal movement of plate 76 from the solid to the dotted linepositions of FIG. 3.-Such means comprises a rod which'has a horizontallyextending portion mounted on a cylindrical support member 112 which isthreadedly engaged at its lower end in the collar 38 as shown in FIG. 4.The horizontal portion of rod 110 is adapted to fit in a bore 114 inmember 112 and to be locked in this position by a locking screw 116. Rod110 is constructed and arranged so that its horizontally extendingportion extends laterally from the top of the reel 30 a substantialdistance to a point where a vertically extending portion thereof isarranged to come into contact with the arm means 90 as is shown in FIGS.1 and 2.

In the use of the apparatus in accordance with the invention for mowinga predetermined area of a lawn, the

first step involved is anchoring the reel means 30 in the ground at thecenter of the area to be mowed. Since this area is normally to be mowedrepeatedly, there is usually provided some form of reel anchoring meanspermanently installed underground, such as the anchoring means 44 shownin FIG. 4. The reel means 30 is then mounted on the anchoring means byinserting the pipe 42 into slots 47 in the pipe 46 and placing the pins48 in a locked position such as is shown in FIG. 4. The line 60 is thenunwound from the reel and the latch 67 at its outer end is secured tothe bracket 68 at the front left end of the mower as is best shown inFIG. 1. The mower, of course, has been placed at the circumference ofthe area to be mowed. The rod 110 and the arm means 90 are located inthe positions such as shown in the drawings. The mower is then startedand the drive engaged and allowed to proceed in a selfpropelled movementfrom the starting position. As the mower proceeds unattended, it causesthe line 60 to wind in a counterclockwise direction about the reel 30 asis viewed in FIG. I. With each revolution, the mower moves closer to thecenter of the reel means and the mower moves in a decreasing spiralmowing the grass as it goes. It will be noted that the cuttings aredischarged toward the outside of this spiral movement through thedischarge chute 20 onto the portion of the lawn which has already beenmowed so that the mower is not burdened with re-cutting the cuttings, asis preferable in grass cutting. When the mower reaches the point closeto the reel means 30, such as is shown in FIGS. 1 and 2, the arm portion96 comes into contact with the rod 110 and as the mower continuesforward movement the plate 76 is pivoted from the solid line to thedotted line position shown in FIG. 3 to place the lower portion of theplate 76 into contact with the outer end of spark plug 14. This shortsthe sparking circuit to ground and stops the operation of the engine,whereupon the lawn mower comes to rest at a position closely adjacentthe reel means 30. However, prior to this, the lawn mower has mowed agenerally circular area of lawn around the reel 30 at the centerthereof.

It will be apparent that various changes may be made in the constructionand arrangement of parts without departing from the scope of theinvention. For example, the parts may be constructed of variousconfigurations to adapt the same for mounting on various types of lawnmowers. Also, the mechanism may be adapted for use with lawn mowershaving spark plugs at the front thereof.

I claim:

1. Apparatus for controlling the operation of a power-operated,self-propelled lawn mower or the like to mow a predetermined lawn areaby self-propelled operation, comprising a reel means adapted to beanchored in a fixed positionat the center of the lawn area to be mowed,line means secured at one end on said reel means, means for attachingthe other end of said line means to a lawn mower so that as said lawnmower is self-propelled it moves in a decreasing spiral path around saidreel means winding said line means thereon, and means for automaticallystopping operation of said lawn mower at a location close to said reelmeans, said automatic stopping means including a rod means mounted onsaid reel means to extend therefrom into the path of said lawn mower asit moves close to said reel means, said line means being mounted on thelawn mower at a position lower than said rod means so that said linemeans is guided underneath said rod means as it winds on said reelmeans.

2. Apparatus according to claim 1 wherein said line means is attached toa front corner of the mower.

3. Apparatus according to claim 1 in which the circumference of saidreel means is less than the cutting width of the lawn mower wherebythere is an overlap in the cutting path of the lawn mower as it moves insaid decreasing spiral path.

4. Apparatus according to claim 1 wherein said lawn mower is of therotary type and is provided with discharge means for the grass on oneside thereof, said means for securing said line means to the lawn mowerbeing located at the front corner of said lawn mower near the sideopposite said one side having said discharge means.

5. Apparatus according to claim 1 wherein said mower stopping meansincludes control means mounted on said lawn mower for movement from afirst position which permits self-propelled operation of said lawn mowerto a second position which stops selfpropelled operation of said lawnmower, said control means being arranged to be contacted by said rodmeans to actuate the same from said firt position to said secondposition.

6. Apparatus according to claim 5 wherein said lawn mower is propelledby means of a gasoline engine powered by a spark plug, said controlmeans including a plate pivotally mounted on said lawn mower formovement from a position clear of said spark plug to a position incontact with said spark plug, and means for grounding said plate when itis in said position in contact with said spark plug to thereby shortcircuit the power supply to said spark plug.

7. Apparatus according to claim 6 wherein said control means includes acontact arm mounted on said plate to project laterally from a side ofsaid lawn mower, said rod means being arranged to contact said contactarm to actuate said plate to pivot from said position clear of saidspark plug to said position in contact with said spark plug.

8. Apparatus according to claim 7 including means for anchoring saidreel means in the ground at the center of said lawn area, said reelmeans having a member extending from the lower end thereof, saidextending position clear of said spark plug.

i i i wk

1. Apparatus for controlling the operation of a power-operated,self-propelled lawn mower or the like to mow a predetermined lawn areaby self-propelled operation, comprising a reel means adapted to beanchored in a fixed position at the center of the lawn area to be mowed,line means secured at one end on said reel means, means for attachingthe other end of said line means to a lawn mower so that as said lawnmower is self-propelled it moves in a decreasing spiral path around saidreel means winding said line means thereon, and means for automaticallystopping operation of said lawn mower at a location close to said reelmeans, said automatic stopping means including a rod means mounted onsaid reel means to extend therefrom into the path of said lawn mower asit moves close to said reel means, said line means being mounted on thelawn mower at a position lower than said rod means so that said linemeans is guided underneath said rod means as it winds on said reelmeans.
 2. Apparatus according to claim 1 wherein said line means isattached to a front corner of the mower.
 3. Apparatus according to claim1 in which the circumference of said reel means is less than the cuttingwidth of the lawn mower whereby there is an overlap in the cutting pathof the lawn mower as it moves in said decreasing spiral path. 4.Apparatus according to claim 1 wherein said lawn mower is of the rotarytype and is provided with discharge means for the grass on one sidethereof, said means for securing said line means to the lawn mower beinglocated at the front corner of said lawn mower near the side oppositesaid one side having said discharge means.
 5. Apparatus according toclaim 1 wherein said mower stopping means includes control means mountedon said lawn mower for movement from a first position which permitsself-propelled operation of said lawn mower to a second position whichstops self-propelled operation of said lawn mower, said control meansbeing arranged to be contacted by said rod means to actuate the samefrom said firt position to said second position.
 6. Apparatus accordingto claim 5 wherein said lawn mower is propelled by means of a gasolineengine powered by a spark plug, said control means including a platepivotally mounted on said lawn mower for movement from a position clearof said spark plug to a position in contact with said spark plug, andmeans for grounding said plate when it is in said position in contactwith said spark plug to thereby short circuit the power supply to saidspark plug.
 7. Apparatus according to claim 6 wherein said control meansincludes a contact arm mounted on said plate to project laterally from aside of said lawn mower, said rod means being arranged to contact saidcontact arm to actuate said plate to pivot from said position clear ofsaid spark plug to said position in contact with said spark plug. 8.Apparatus according to claim 7 including means for anchoring said reelmeans in the ground at the center of said lawn area, said reel meanshaving a member extending from the lower end thereof, said extendingmember carrying a laterally projecting pin means adapted to be removablyengaged by said anchoring means.
 9. Apparatus according to claim 7wherein said contact arm is adapted to be collapsed to a retractedposition and including means for biasing said plate to said positionclear of said spark plug.